Eighteen boys with Factor VIIII and/or IX deficiency have undergone a liver biopsy for possible HCV. Liver biopsy was done only after normalization of Factor VIII or IX levels with Factor VIIIi or IX. There was a spectrum of hepatitis C related liver injury. Three boys had normal liver biopsies and were PCR negative. 15 had mild to moderate hepatitis. All children were treated with alpha-interferon which was tolerated reasonably well except for fatigue. 50% of children became PCR negative at 6 months; of the 10 who have finished therapy, all were PCR+ negative at 12 months after initiation of therapy. The significance of this pilot investigation is the following:1) New information regarding the spectrum of liver histology in HCV-infected hemophiliac children 2) Confirmation of the observation in adults that there can be histoogic evidence of hepatitis in the absence of elevated serum aminotranferases 3) Confirmation that serum PCR is the best way to follow response to alpha-interferon therapy of HCV infected in children